In article ,
Joe wrote:
I just managed to get hold of unbuilt Heathkit alarm clock GC-1107. The
electrolytics were dry and the speaker is shot. Finding replacement caps
was easy, but does anyone here know the impedance of this 2,5" speaker?
Is it "normal" 8 ohms or something more exotic?

Presumably it's the cone which has gone? If so the coil should still be ok
so measure the DC resistance. That will be near enough the impedance for a
guide. Early small transformer less (output) small transistor amps
sometimes used 35 ohm speakers, but they got round this when silicon
transistors arrived.

--
Small asylum seeker wanted as mud flap, must be flexible and willing to travel

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
In article ,
Joe wrote:
I just managed to get hold of unbuilt Heathkit alarm clock GC-1107. The
electrolytics were dry and the speaker is shot. Finding replacement caps
was easy, but does anyone here know the impedance of this 2,5" speaker?
Is it "normal" 8 ohms or something more exotic?

Presumably it's the cone which has gone? If so the coil should still be ok
so measure the DC resistance. That will be near enough the impedance for a
guide. Early small transformer less (output) small transistor amps
sometimes used 35 ohm speakers, but they got round this when silicon
transistors arrived.

--
Small asylum seeker wanted as mud flap, must be flexible and willing to
travel

Dave Plowman London SW
To e-mail, change noise into sound.

Unfortunately the cone is fine, but the coil reads several megaohms.

-Jan

"Joe" wrote in message
...

"Dave Plowman (News)" wrote in message
...
In article ,
Joe wrote:
I just managed to get hold of unbuilt Heathkit alarm clock GC-1107. The
electrolytics were dry and the speaker is shot. Finding replacement caps
was easy, but does anyone here know the impedance of this 2,5" speaker?
Is it "normal" 8 ohms or something more exotic?

Presumably it's the cone which has gone? If so the coil should still be
ok
so measure the DC resistance. That will be near enough the impedance for
a
guide. Early small transformer less (output) small transistor amps
sometimes used 35 ohm speakers, but they got round this when silicon
transistors arrived.

--
Small asylum seeker wanted as mud flap, must be flexible and willing to
travel

Dave Plowman London SW
To e-mail, change noise into sound.

Unfortunately the cone is fine, but the coil reads several megaohms.

-Jan

Sound quality certainly hasn't been a high priority on any radio alarm clock
I've ever had so maybe you should concentrate on what *IS* important on a
radio alarm clock - the speaker should be loud enough and the output devices
should not overheat at maximum volume. If an 8 Ohm works - is loud enough
and doesn't overheat anything then fine, otherwise 16 Ohm aren't that hard
to find - 35 Ohm do exist but are harder to find.

In article , "Joe" wrote:

"Dave Plowman (News)" wrote in message
...
In article ,
Joe wrote:
I just managed to get hold of unbuilt Heathkit alarm clock GC-1107. The
electrolytics were dry and the speaker is shot. Finding replacement caps
was easy, but does anyone here know the impedance of this 2,5" speaker?
Is it "normal" 8 ohms or something more exotic?

Presumably it's the cone which has gone? If so the coil should still be ok
so measure the DC resistance. That will be near enough the impedance for a
guide. Early small transformer less (output) small transistor amps
sometimes used 35 ohm speakers, but they got round this when silicon
transistors arrived.

--
Small asylum seeker wanted as mud flap, must be flexible and willing to
travel

Dave Plowman London SW
To e-mail, change noise into sound.

Unfortunately the cone is fine, but the coil reads several megaohms.

Rip the cone apart and see if you can find a reading. The wire usually breaks
away from the coil.

greg